Synergistic CH Binding Sites in Hydrogen-Bonded Supramolecular Framework for One-Step CH Purification from Ternary C2 Mixture.

Purification of CH from the ternary C2 hydrocarbon mixture in one step is of critical significance but still extremely challenging according to its intermediate physical properties between CH and CH. Hydrogen-bonded organic frameworks (HOFs) stabilized by supramolecular interactions are emerging as a new kind of adsorbents that facilitate green separation. However, it remains a problem to efficiently realize the one-step CH purification from CH/CH/CH mixture because of the low CH/CH selectivity. We herein report a robust microporous HOF (termed as HOF-TDCPB) with dense O atoms and aromatic rings distributed on the pore surface which provide CH and CH preferred environment simultaneously. Dynamic breakthrough experiments indicate that HOF-TDCPB can not only obtain high-purity CH from binary C2 mixture, but also firstly realize one-step CH purification from ternary CH/CH/CH mixture, with the CH productivity of 3.2 L/kg (>99.999 %) for one breakthrough cycle. Furthermore, HOF-TDCPB displays outstanding stability in air, organic solvents and water, which endow it excellent cycle performance even under high-humidity conditions. Theoretical calculations indicate that multiple O sites on pore channels can create synergistic binding sites for CH, thus affording overall stronger multipoint interactions.